In color photographs that are now widely produced, particularly color prints, use is made of color reproduction based on the so-called subtractive color process, wherein a yellow dye, a magenta dye, and a cyan dye are used as color dyes. Since the color reproduction range of the obtainable dye image is determined by the hues of the above respective dyes that are used as subtractive colors, an important subject to those skilled in the art is how to develop a dye having excellent absorption characteristics.
In photographic materials, such as color photographic printing papers, usually, a technique is used wherein emulsion layers containing silver halide emulsions sensitive to light in the range of wavelengths of blue, green, and red are provided and, in the emulsion layers, so-called couplers (generally a combination of couplers is used, which will form dyes having complementary relationships to the lights having wavelengths to which the emulsions are sensitive) are contained. The couplers will form the above-described dyes upon coupling reactions with the oxidized product of an aromatic primary amine developing agent, that is produced when the silver halide emulsions exposed to light are developed after the photographic material is exposed to light imagewise and is processed with a color developer containing that aromatic primary amine developing agent, whereby a color image is formed. As these dye-forming couplers, so-called active methylene compounds are commonly used, and specific examples are pivaloylacetoanilides as yellow dye-forming couplers, 5-pyrazolones or pyrazoloazoles as magenta dye forming couplers, and phenols and naphthols as cyan dye-forming couplers.
Out of these dye-forming couplers, phenols or naphthols used as cyan dye-forming couplers have such defects as that the short wavelength side of the major absorption of the red light region that will present cyan hue is broad, and they have subsidiary absorption in the blue light region in addition to the major absorption.
With respect to cyan couplers that obviate these defects, various suggestions have been made, for example, imidazole couplers described, for example, in JP-A ("JP-A" means unexamined published Japanese patent application) No. 226653/1988 or 61946/1991, and couplers having a structure wherein a pyrazole ring is condensed with a nitrogen-containing heterocyclic 6-membered ring, as described in JP-A No. 135442/1990 or 136855/1990, can be mentioned, but they are not satisfactory in view of the color hue and the color-forming property.
On the other hand, in the production of color prints, to meet the shortening of the time for delivery and the demand for high efficiency, a technique of processing rapidly a silver halide emulsion having a high silver chloride content is disclosed in International Publication WO 87/04534. Further, for the purpose of saving resources and reducing pollution, a method of reducing the replenishing amounts of color development processing solutions and decreasing the discharge is disclosed in JP-A No. 70552/1986 or 106655/1988.
From this viewpoint, the inventors investigated couplers whose color hue is sharp and without undesirable absorption, which couplers have high color-forming property, and found a cyan coupler represented by formula (I) or (II) given below, but when evaluating a photographic material by combining the cyan coupler with a high-silver-chloride emulsion useful for rapid processing, it became apparent that there was a grave problem that had not been expected hitherto. That is, it was found that when the cyan coupler is combined with a silver halide emulsion having a high silver chloride content to prepare a photographic material, fogging readily occurs at the part of the photographic material where pressure has been applied. This phenomena is noticeable when a projection under a light load is passed on the photographic material surface at a high speed and this risk is expected to happen when a print is formed by using a high-speed printer commonly used in usual color photofinishers and the like. If such a problem occurs, the print quality is impaired conspicuously. It is a serious obstruction when a photographic material in which the cyan coupler of the present invention is combined with a high-silver-chloride emulsion is put to practical use.
When such a photographic material was continuously processed with the replenishing amount of a color developer decreased, a problem arose that the contrast lowered with an increase of the processed amount.